Photo Markus SCHWEISS
The Col of Tende (Tende Pass) was already used by the Romans. The road linking Torino and Nice climbed here. In 1860 when the county of Nice became French, the upper Roya Valley (Tende, la Brigue) remained Italian. The relationship between the 2 countries became tenser at the end of the 19th century and forts were built on both sides of the border. The forts at the Col of Tende were therefore built by Italy. The Central fort is surrounded by 5 other fortifications, all of them built between 1881 and 1883. A cablecar brought the supplies in winter when the forts could not be reached. It started in Panice, on the Northern side. The forts were not used during WWI, France and Italy being allied then. These forts are an impressive set which can be reached hiking or with mountain bikes. Chart : IGN 3841OT Vallée de la Roya, Vallée des Merveilles 1/25000
Between WWI and WWII Italy added a new system of defence, "vallo alpino" with more than 120 forts in the upper valley of the Roya, most of them dug into the rock and today abandoned.
In 1947 the whole Roya valley became French.
The Col of Tende where the present border passes is crossed by a tunnel which avoids the former and very windy road.
To go there the easiest way is to go via Vintimiglia, in Italy (use the highway, you will pay the toll using euros, just make sure you have some change). That's where the roads will be the easiest. If you stay in France, you will have to pass two passes with windy roads and hair-pins curves. : the Braus pass before Sospel and then the Brouis pass.